Development of three-dimensional position sensor for the digestive tract

Video capsule endoscopes are partly applied to clinical use. However, measurement technologies of capsule position in the digestive tract are not established yet. Therefore, the purpose of this study is to develop three-dimensional position sensor which can measure capsule position in the digestive tract. Three coils are arranged perpendicular in the capsule. The sensor generates electromotive force induced by magnetic field generator placed outside of a living body. By measuring induced electromotive force, we can calculate the distance between the sensor and the magnetic field generator. Although wireless is an ideal method for position measurements of capsule endoscope, this sensor is connected to computer through a thin cable because of electric power requirement.